虚拟惯量控制对直驱风电机组载荷影响的分析及评估

Analysis and Evaluation of Impact of Virtual Inertia Control on Load of Direct-drive Wind Turbine

针对虚拟惯量控制诱发风电机组机械载荷的问题,开展虚拟惯量控制对采用直驱永磁同步发电机(D-PMSG)的风电机组载荷影响的理论分析和仿真评估研究。从叶片、塔筒等机械结构低阶模态出发,建立虚拟惯量控制下D-PMSG线性化多体动力学模型,并通过线性化多体动力学模型分析虚拟惯量控制对机组载荷的影响机理。采用软件联合建模方法,构建涵盖永磁同步电机及其控制、电网、机械和气动特性等的D-PMSG非线性机电耦合模型。依据冲击载荷最大值、最大变化幅度百分比及等值疲劳载荷等指标,通过所建立的非线性机电耦合模型仿真分析并量化评估虚拟惯量控制对机组冲击载荷和动态疲劳载荷的影响。结果表明,D-PMSG附加虚拟惯量控制后,电网侧频率突变会使得传动轴和塔底侧向出现显著冲击载荷,且其随虚拟惯量时间常数增大而增大,在湍流风运行工况下机组传动轴和塔底侧向等值疲劳载荷较无附加虚拟惯量控制均有所减小。

Considering issues of wind turbine mechanical loads induced by virtual inertial control,the theoretical analysis and simulation evaluation are carried out for the influence of virtual inertial control on the loads of the wind turbine adopting direct-drive permanent magnet synchronous generator(D-PMSG).Focusing on the low-order modes of mechanical structures such as blades and towers,a linear multi-body dynamic model is established for the D-PMSG with virtual inertial control,through which the mechanism is investigated for the influence of the virtual inertial control on its loads.The D-PMSG nonlinear electromechanical coupling model,which covers the PMSG and its characteristics of control,power grid,mechanical structures and aerodynamics,etc.,is constructed for D-PMSG by utilizing the method of software joint modeling.The influence of virtual inertial control on the impact loads and dynamic fatigue loads is simulated through the nonlinear electromechanical coupling model,and the quantitative evaluation of the influence is further carried out by utilizing indicators such as the maximum value of impact loads,the percentage of maximum change and the equivalent fatigue loads.The results show that,when the system frequency changes suddenly,significant impact loads,which increase with the virtual inertial time constant,appear in the shaft and the tower side-to-side for DPMSG with virtual inertial control.It also shows that,under the operation of turbulent wind conditions,the equivalent fatigue loads on the generator drive shaft and tower side-to-side are reduced compared with no virtual inertial control.